<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>promise.all</title>
</head>

<body>
    <script type="text/javascript">
    async function firstAsync(){
        return 1
    }
    console.log(firstAsync()) //执行结果：Promise {<resolved>: 1}
    firstAsync().then(val => {
        console.log(val)    //执行结果：1
    })
    </script>
</body>

</html>